With rapid development of electronic and information industries, image pickup devices become essential electronic devices in our daily lives. Generally, image pickup devices are used to take photographs or record video data. In addition, image pickup devices are also applied to web cameras for making a video conference. Recently, the built-in image pickup devices of notebook computer or the external pickup devices connected with desktop computers are gradually adopted.
With increasing development of digital techniques, text documents are gradually created as electronic files. Generally, text documents are scanned by scanning apparatuses and then saved as electronic files such as PDF (Portable Document Format) files. In a case that no scanning apparatus is in communication with the notebook computer, the images of simple documents such as single-sided papers or business cards may be captured by the computer peripheral devices (e.g. image pickup devices). The images captured by the built-in image pickup device are usually saved as JPEG (Joint Photographic Experts Group) files. However, most users prefer using scanning apparatuses to scan the text documents as PDF files because the texts and signs contained in the PDF files are readable by the computer systems and may be converted into editable text files
As known, an optical character recognition (OCR) technique is a process of capturing an image of a document and then extracting the texts from that image. After an image of a document is captured by an image pickup device and saved as a JPEG file, the JPEG file may be analyzed according to the OCR technique. As a consequence, individual texts or signs contained in the JPEG file will be recognized and converted as an editable text file. Since the OCR technique is well established, image pickup devices are gradually adopted to acquire electronic image files of the documents.
Nowadays, a mouse having a shooting function has been introduced into the market. Generally, an image pickup device is installed on a casing of this mouse. The mouse may be used to control cursor movement of a computer system or select an icon shortcut. While the operation of the computer system is controlled by the user through the mouse, the image pickup device of the mouse may be used to shoot the document to acquire an electronic image file of the document.
Generally, there are two ways of using the image pickup device of the mouse to shoot the document. In the first way, the document is held by a user's hand, and the mouse is placed on a working plane (e.g. a desk plane) to shoot the document. In the second way, the document is placed on the working plane, and the mouse is held by the user's hand to shoot the document that is placed on the working plane. The way of holding the document by the user's hand and the way of holding the mouse are unsatisfied because the obtained images (i.e. the electronic image file of the document) are usually blurred. If the document or the mouse is handheld, the document or the mouse is readily rocked because of a handshaking action. Consequently, the document is blurred.
Moreover, in views of cost-effectiveness, the lens of the image pickup device of the mouse usually has a fixed focal length, and the focal length of the lens is not adjustable. In a case that no preview screen is used, it is difficult to precisely allow the image pickup device to focus on the document to shoot the document. Under this circumstance, the document image acquired by the image pickup device is still blurred.
Therefore, there is a need of providing a mouse with a shooting function and an image pickup system using such a mouse in order to enhance the shooting quality.